Fatigue and medication

Hi, my mum recently had full hysterectomy and also has had biopsies off her breast. Fortunately the hysterectomy has done its job, but my mum has been put on Anastrozole 2 weeks ago and the fatigue she has is immense. I understand you can feel tired, but she just can’t keep her eyes open. She has said to me, she is so exhausted and has been so emotional. Does anyone have any advice? She has only been on it two weeks.